[PATCH] D93998: [InstSimplify] Fold out-of-bounds shift to poison

[Nikita Popov via Phabricator via llvm-commits]

nikic created this revision.
nikic added reviewers: aqjune, spatel, lebedev.ri.
Herald added subscribers: arphaman, hiraditya.
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Make InstSimplify return poison rather than undef for out-of-bounds shifts, as specified by LandRef:

> If op2 is (statically or dynamically) equal to or larger than the number of bits in op1, this instruction returns a poison value.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D93998

Files:
  llvm/lib/Analysis/InstructionSimplify.cpp
  llvm/test/Transforms/InstCombine/add-shl-sdiv-to-srem.ll
  llvm/test/Transforms/InstCombine/out-of-bounds-indexes.ll
  llvm/test/Transforms/InstCombine/phi-shifts.ll
  llvm/test/Transforms/InstCombine/shift.ll
  llvm/test/Transforms/InstSimplify/shift-knownbits.ll
  llvm/test/Transforms/InstSimplify/shift.ll
  llvm/test/Transforms/InstSimplify/undef.ll

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